Factory Timing By Clank (Read 2,024 times)

[Clank]

Anybody ever seen this on a new 1P39QMB before? I'm a little baffled.

[adamhoyer]

 here is mine

[Clank]

So I stuffed a 47mm bbk in today. I'm NOT impressed. It actually is going slower. I also installed a Keihin 19mm with a 85jet. The only thing I can think of is the ported and polished head I bought was jacked or sumtin. thought i had pics of the ports but they where almost twice the size of the stock head. Anyone got any experience or knowledgeable suggestions. It's literally going 10mph slower. In so bummed and P.O.'d

[Alleyoop]

You got two different heads, one has 64mm Valves the other has 69mm Valves. So you would need a different Rocker Arm assembley on either one. Which one is stock and which one is the head you bought.
Alleyoop

[Bashan]

Also, you might need to dial in the carb, pipe, and jet after you get what Alley mentioned straightened out. So don't despair, these things take some time.

[Clank]

Ya the head I bought I was told it was a 69mm but I got a 64mm so I swapped the valves cause all I have are 69mm rocket assemblies. Some ppl have said that the 64 are better but no seems to have a reason to why. I'm thinking of putting the stock head back on cause of the massive porting this yahoo did whom sold the bbk to me.

[Clank]

I also installed a A9 cam with it. And has anyone seen factory timing like this. I have 2other 1P39QMB's and neither of them line up like this. Is it possible the flywheel was installed wrong? I've never removed on so I'm not sure if the markings are wrong or if the flywheel is in the wrong position.

[Clank]

Here's the port pics hopefully you can see what I was talking about yahoo doing a port job. He kicked the fire truck out of the valves.

[Alleyoop]

The heck with the porting I am concerned with the valves, I see no valve stem on the one on the left that sucker is sticking out to far. What did you do? you apparently messed with some crap and swapped stuff around. The timing I am not concerened about either that looks good to me, the line before for "T" is when it is at TDC so it is pointing at the line before which most motors do.

And you cannot put the flywheel on wrong because it slips onto the woodruff key, unless the woodruff key is missing and or damaged then the flywheel can rotate out of position.
Alleyoop

[Clank]

Those pics where the spring is not attached was taken right after I swapped them. The one the right is the new head with now the 69's I took out of the stock head on the left.
And I guess the timing pic is mis leading cause the indicator is @ 9 o'clock, the "T" is at about 930 & the line is at or just pass 10 o'clock. It fired right up but something is wrong.2014 Taotao ATM50-A BBK first fire:
Just listen it's not valves, I thought it was exhaust leak but it's tight.

[tvnacman]

you sitting on a whole host of problems and might be making more .Stop running the engine with the exhaust leak (make a lot of trouble for yourself) . You can not set a/f with a leaking exhaust , you can not set a/f with bad valves . Ok I guess you bought a port and polished head with valves installed ? The valves that it came with were no good for your set up so you removed the matched valves and used your old ones (did you lap your old valves) . So you start it up and go for a ride with a leaking exhaust and you lost 10 mph .

What is the diameter of the old piston ?
Are you getting bogging , backfiring , popping farting noises loss of power in the power band ?
Do you feel an increase in power on take off ?

John

[Clank]

39mm, yes it feels it has a little more torque in take-off till about half throttle then it just flatlines. Lap? They're new heads. Weird noise yes! Exhaust leak no. Where are you going with this?

[tvnacman]

new top end rebuild with bbk new carb what were your old jet sizes in your old carb and what are the new jet sizes . Lap=grind/polish valve seat to valve for a good seal.

Do you have the tool to remove the flywheel ? I would like to get a good look at the timing marks in relation to the pulse magnet and keyway .

The noise sounds like an exhaust leak it could be a knock , did you have a perfect running scooter before you started ?

John

[cyborg]

TV is right if you changed valves in the head they must be lapped (lightly ground to mate correctly) or they won't seal ,,, it is metal to metal so it has to be damned near perfect,,,and Alley is correct as well,,,i see no valve stem tip in either intake or exhaust pic,,,also as a side having huge ports does not mean more power,,,(altho in the pics they do not look radically altered),,,,intake velocities are very important for proper cylinder fill,,,,when things are right it creates a condition called inertia charging which makes for a better cylinder fill,,,,= more power

[cyborg]

Where is Clonedrone when you need him